in the works: Giant Monsters

[Juzza]

Or if you can't and want to do something with blood vengeance, there is an artifact that grants +0 Blood Vengeance, could give them that.

I'm somewhat unsure of what you can do with making your own artifacts though you also may be able to make your own unique items to go with the unique units to grant them certain abilities if you can't add them any other way.